Here is my first attempt at printing a part with a raft and multiple pieces in the same print. I looked at quite a few models on thingiverse.com and chose this model based on its multiple pieces and the letters on one side that says 1/4" drill bits.
The overall print went well and although the raft layer was difficult to remove the printing went very well and was a succsess.
In this instructable I will share some tips that I learned while printing this drill bit holder on a Type A Machine where I made it at Techshop http://techshop.ws.
Submitted by SFlettering for the Instructables Sponsorship Program
Step 1: Skirt Layer of 3D Print - Starting With a Raft Layer
Some of the initial errors that are encountered when using a 3D printer include the initial laying down of the PLA into a flat surface so that a print can take place on top. Notice how the raft layer in skirt style printed a pattern that includes several errors. I estimate that the nozzle was a tad too far away and that initially the first layer did not stick.
If you are willing to settle for a bit lower quality the print nozzle and 3D printer have a greater tolerance to print shapes that have a few layers that are imperfect at the base. A greater tolerance in this case means that even with a few errors in the print as shown below the other layers will go down better as you will see in steps 3 and 4.
Step 2: Starting the Multi Part Print
The initial test was to see how many PLA "strings" were left behind when printing multiple pieces and moving from one piece to the next. When printing between pieces there is a settings that allows the print nozzle to "wipe it nose" and clean off between layers that can improve print quality if there are too many connected PLA "strings" between pieces.
The easiest way based on experience to deal with little strings between separate pieces is to cut them off with a utility knife. Initially when I imagined using a 3D printer I thought each print would be automatically perfect. After practice I learned that about half of the prints that are designed well will print well when downloaded from thingiverse
Step 3: Growing Slowly
Here the printed piece is creating too large layers that compromise almost 50% each and contain the writing for the final piece. I did not end up using the third thin piece shown below on the left.
Step 4: Almost Done Printing - Draft Mode Print Is Good
As it continues to print I notice that each layer is working out better than the last layer and that the overall print quality is good even when printing in draft mode at (200-250 um).
I think if the print quality was improved the readability of the text on the side of this piece would improve.
Step 5: Final Print With Raft Layer
Here you can see the final print as it completed on the machine and what it looks like while the raft layer is still attached.
To get the final piece ready you can tear or cut off the raft layer.
In this step you can also see the bottom of the raft layer to show the errors that were made initially did not create problems in the final print.
Step 6: Multiple Parts Almost Done - a Raft Layer Mostly Removed - Hole Clearing Stage
After removing the pieces from the raft layer each piece also needed to have each hole cleared out of plastic strings from the print. By clearing each hole it also made the removal of the raft layer easier.
Step 7: Final Cleaned Up Part - Notice Quality of Letter Writing "1/4" Bits" on Side
Here you can see the quality of the final print with the lettering lined up in the image. The overall quality of this print is great, but the lettering is very hard to read for someone who does not know what it says.
My experience printing a piece with multiple parts demonstrates that when using a raft layer you can get decent quality prints even in draft mode.